<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            color: blue;
        }
        .clazz{
            color: green;
        }
        #d1{
            color: black;
        }
        a{
            text-decoration: none;
        }


        a:hover{
            color: green;
        }



    </style>


</head>
<body>
    <!--内联的方式-->
    <div style="color: red">div1</div>
    <!--内部方式-->
    <div>div2</div>
    <!--link标签-->
    <div>div3</div>

    <div class="clazz">clazz1</div>

    <div id="d1">3</div>
    <a href="http://www.baidu.com" target="_blank">href</a>
    <ul>
        <li>1</li>
        <li>2</li>
        <li>23</li>
    </ul>
</body>
</html>